U.S. Pat. No. 5,100,889 to Misra et al discloses interphenylene 7-oxabicycloheptyl substituted heterocyclic amide prostaglandin analog TXA.sub.2 antagonists having the structure ##STR1## and including all stereoisomers thereof, wherein m is 1, 2 or 3; n is 0, 1, 2, 3 or 4;
Z includes ##STR2## wherein Y is O, a single bond or vinyl (--CH.dbd.CH--), with the provisos that when n is 0, Y cannot be 0; and when Y=vinyl, n=0; PA1 R is CO.sub.2 H, CO.sub.2 lower alkyl, CO.sub.2 alkali metal, CH.sub.2 OH, CONHSO.sub.2 R.sup.3, COHNR.sup.3a, or ##STR3## (--CH.sub.2 -5-tetrazolyl); X is O, S or NH; PA1 R.sup.1 is hydrogen, lower alkyl, lower alkenyl, lower alkynyl, aralkyl, aryl, cycloalkyl, cycloalkylalkyl, cycloheteroalkyl, cycloheteroalkylalkyl, heteroaryl or heteroarylalkyl, or amide ##STR4## wherein t is 1 to 12 and R.sub.a is lower alkyl, aryl, cycloalkyl, or cycloalkylalkyl); PA1 R.sup.2 is hydrogen, lower alkyl, aryl, or aralkyl; PA1 R.sup.1 and R.sup.2 together with the nitrogen to which they are linked may form a 5- to 8-membered ring; PA1 R.sup.3 is lower alkyl, aryl or aralkyl; and PA1 R.sup.3a is hydrogen, lower alkyl, aryl or aralkyl. PA1 R.sup.2 is H, aliphatic hydrocarbon group or an aliphatic hydrocarbon group substituted by an aromatic group directly or through an O or S atom; PA1 R is --NH.CO.NH--R.sup.3 or --NH.CS.NH--R.sup.3 where R.sup.3 is an aliphatic hydrocarbon group, an aromatic group or an aliphatic hydrocarbon group substituted by one or more groups directly or through an O or S atom.
or
The above Misra et al patent covers the thromboxane A.sub.2 receptor antagonist BMS180,291 which has the structure ##STR5## and the name [1S-(1.alpha.,2.alpha.,3.alpha.,4.alpha.)]-2-[[3-[4-[[pentylamino) carbonyl]-2-oxazolyl]-7-oxabicyclo[2.2.1]hept-2-yl]methyl]benzenepropanoic acid or a pharmaceutically acceptable salt thereof such as its sodium salt, potassium salt, calcium salt or magnesium salt.
For matter of convenience, BMS 180,291 will hereinafter be referred to as "ifetroban".
Published GB application 2217597A to National Research Development Corporation discloses use of compounds having thromboxane antagonist activity in the treatment of dysmenorrhea, endometriosis and fibroids, which may have the structure ##STR6## wherein ##STR7## is a bicyclo-heptane, -heptene, -octane or -octene group, including ##STR8## R.sup.1 is a 6-carboxyhex-2-enyl group or modification thereof, V and V.sup.1 either each separately is H or together are the second bond of a C--N double bond;
EP535924 and EP535923, each filed by Merck Frosst Canada, disclose various indole leukotriene inhibitors which have thromboxane antagonist activity, and thromboxane synthetase inhibitory activity, and which may optionally be used with an NSAID for treating dysmenorrhea.
U.S. Pat. No. 5,312,818 to Rubin et al discloses a combination of a thromboxane A.sub.2 receptor antagonist and an anti-inflammatory agent to treat inflammatory conditions, such as arthritis, while inhibiting formation of and/or treating ulcers.